Door control for the rear lifting mechanism of two post lifts



Oct. 13, 1953 4l. v. K. HOTT ET AL DOOR CONTRO 2,655,224 L FOR THE REARLIFTING MECHANISM 0F rrwo PosT LIFTS Filed March 2o, 195o 5Sheets-Sheet` l INN... NA

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l. V. K. HOTT ET AL DOOR CONTROL F' OR THE REAR LIFTING oct. 13, 1953y lMECHANISM OF'TWO POST LIF'TS 5 Sheets-Sheet 2 Filed March 20, 1950 l l.llln H IIAIIIIIIIIIIIIIIQIIIHHHIIIIIIIIIIIN' Inlll H .lllillllh lllll"Il "MMU INVENTORS /O/V M M H0 7'7 KENNETH .15'.V 5564./

Oct. 13, 1953 v. K. HOTT ET AL DooR CONTROL RoR THE REAR LIFTINGMECHANISM OF TWO POST LIFTS 3 Sheets-Shea?l 3 Filed March 20, 1950 .m mm V05. N y? M M Patented Oct. 13, 1953 noon -corrraoLroR THE REARLIFTING MECHANTSM oF 'rWo Pos'r LIF'rs Ion V. K. Hottand Kenneth E.Berk, Dayton,

Ohio, assignors to The Joyce-Cridland Company, Dayton, Ohio, acorporation of Ohio Application March 20,- 1950, Serial No. 150,696

y 7 claims. (ci. lsv-8.62)

This invention relates to an automobile lifting mechanism, and moreparticularly to the` lifting mechanisms of the type in which thesuperstructure is movable into and out of a pit below the level of afloor.

The invention is here shown as embodied in the rear lifting mechanism ofa two post lift which is movable into and out of a pit and is of thegeneral type shown in the Webster and Berlr application, Serial Number739,132, led April 3, 1947, now Patent No. 2,588,597. Y

One object of the invention is to provide an improved and simplifiedmechanism for controlling the opening and closing of the doors ofthe p Aspecific object of the invention is to provide a door controllingmechanism in which the connection between an actuating device and -adoor is yieldable to permit the movement of the actuating device withrelation tothe door when eX- cessive resistance is offered tothe openingof the door.

Other objects of the invention may appear as the mechanism is describedin detail.

In the accompanying drawings Fig. l is a top plan view of va. pitenclosing the lifting mechanism, with the doors closed; Fig. 2 is alongitudinal sectional view taken on the line 2--2 of Fig. l, showingthe pit housingpartly broken; Fig. 3 is a staggered transverse sectionalview taken on theline 3- 3 of Fig. l; and Fig. 4 is a sectional detailtaken on the line lI--4V of Fig. 2.

In these drawings we have illustrated one embodiment of the inventionand have shown the same as applied to a hydraulic lifting mechanism of aknown type, but it is to be understood that the mechanism may takevarious forms and may be applied to lifting mechanisms of various kindswithout departing from the spirit of the invention.

In that embodiment here illustr-ated the vlift is hydraulically operatedand comprises a cylinder 5 mounted in the ground below the bottom of apit 6 with its upper end extending into the pit. A piston 'I mounted inthe cylinder has rigidly secured thereto a cross head 8 and parallelrails S are secured to the respective Vends of the cross head adapted tosupport the rear axle ofvan automobile on the lift. The pit may be ofany suitable size and shape to receive the superstructure of the liftbut preferably itis `of an H,- shape, having parallel side portionsIll'to receive the rails 9 and a transverse portion II to receive thecross head 8. The upper ends of these portions cf the pit constituteopenings in a iioor I2 through which the cross head and rails may moveinto and out of the pit. The upper edgeofeach wall of the pit isprotected by an angle bar`"I3, the upper ange of which is at floor1evel`and which constitutes a door support. Y Each of the floor openingsI0 and II is provided with a closure. Preferably each of the side, orparallel; openings IG is closed vby a single door hinged at itsouteredge to the adjacent bar I3, as shown at I5. The transverse openingII is closed by a pair of doors I6 hinged at their outer edges to thebars I3 at the respective sides of the opening,` as shown at I'I. Y@

Means are provided for opening the several doors to permitthesuperstructure to movevinto and out of the pit and for closing allthe doors while thesuperstructure is in the pit. In the presentarrangement the transverse doors I6 are moved to their open positions bycontact with the cross head :3 as the lift moves upwardly and areprovided with parts I8 to engage and move over the respective edges ofthe cross head and to then eng-age the lifting element, or piston I. Theaxes about which the doors I6 move. are spaced one from the other adistance somewhat greater than the diameter of the lifting' element sothat when in engagement with the lifting ele-` ment thesev doors aresupported thereby'in inwardly inclined positions'and are moved `by.grav-f ity to their closed positions when the superstructure passesbelow door level. The doors i6 kare supported in their substantiallyhorizontal closed positions byrstuds, or rods, I9 mounted on :andextending upwardly from the cylinder A5 and each adapted to engage theinner edges of both the doors. These doors, when in their open'posi-ltions, are so positioned with relation to the transverse opening as toprevent a person working under an automobile on the lift from steppinginto the opening. Y

The opening and closing movements of the side doors I4 are alsocontrolled by the movement of the lifting element and for this purposethere is mounted in the pit an actuating mech. anism, the operation ofwhich is controlled by? the lifting element and which is so connectediwith the respective doors I4 that those doors; will be opened when thesuperstructure moves. toward the doors from either below or above. the.`same, and will be closed when the superstruc-A ture has moved throughthe floor openings. The: connection between the actuating mechanism andthe doors includes av yieldable element of' sufficient strength to openthe doors when theopening movement thereof is unresisted but. td

3 yield and permit the actuating mechanism to move with relation to thedoors when the opening movement of the latter is strongly resisted. Thisactuating mechanism may take various forms. Preferably it comprises arock shaft 20 extending transversely A,to the cylinder 5 below thelowermost positionfof the superstrutireiand rotatablynounted inbearingsZ'I. Mountedion the shaft adjacent each end thereof is a crankarm 22 the outer end of which is movably connected with the lowerportion-'onarigidsmember, or rod, 23, which is pivotally 'connected fat24 with the corresponding door I4. Theorank arm is connected with therod-forfiiiovenient with relation thereto but is normallyheldagainstsuch movement by spring means. 4Preferably a bearing member 25 ispivotallyicnnectedlwith 4 roller and hold the crank arm 34 in theposition to which it has been moved so as to prevent the doors fromclosing until the superstructure has passed through the openings in thefloor, and the lower cam surface 32 will then engage the roller andpermit the crank armll to move afclck'wise direction, therebyierxittingthe doors to close. As best shown inig. 3`the doors -w-hen in fully openpositions extend inwardly "at a slight angle to the vertical so thatwhen theicral'ik-arm 53'! released by the cam the f'doors "willfr'noveto their closed positions by liigravity.. 'fthe fsuperstructure movesdowniis the outer end of the crank arm 22 for movement about ahorizontal axis and is provided 'with J'a vertical opening through'whichthe rod 23 ex- H tendsythe rod having'at 'its lower end a head, ornut,`2Ifto retain the bearing member thereon. Acmpression spring 42I ismounted about'the i'od between the bearing member A25 anda stop 'n-anintermediate portion of the rod. In the present instancethe rod 23 isformed in two parts `-which are adjustably connected one with the otherby a turn'buckle`28 and this turnbuckle constitutes the stop'whichengages one end of the-springl. Whent'h'ecrank ar-rn 22 is moved aboutitsa-Xis in a counterclockwisedirection, asishown-'in "ig.2, andtheopening movement of the door I4 connected therewith-is'unresisted,the'spring 21 will hold-the bearing member 25 against 'material movementylengthwise of the ro'dandthe door will be opened. Should substantialresistance be oiered -to the opening movement of'the door, `as by anautomobile so positioned above the uit that onewheei thereof overlapsVthe-'dooig'the spring 2l will be compressedand-the crank arm will moveVvwith relation tothe rod, thus preventing injury-to the mechanism andaffording suiiicient time for the operator-to note that the door -isnotopening andf'to'interupt the operation ofthe-*actuating mechanism. Y

'The"means forA actuating the Irock lshaft 20 may" 'be "of any` suitablecharacter and --as here shown 'it comprises an'elongate cam 29 mountednan elongate kvmember which is rigidly seuredto the cross head 8 andextends into-the grundbelow theA pit so that it moveswith `theliftingelement. The 'upper u'and-lowerportions f the cam' are'providedwith relativelyflonginlinedoam surfaces,`f-3I 'and-`-32, connected-onewith the other by avert-ical ledge portion 13a. Rigidlyi securedto-therock shaft20 `is lasec'ond crank arm 34 or cam follower which extendsinwardly to`a position to bey engaged bythe-cam 29, the crank arm havingthereon-afrollerBS tot providey irllin'g "contact betweenthe* 'sameiandthecam. x*Tl-ie crankarm .Q4-is 'sofconne'ctd with 'theockirshaftthat-when thati'shaft is in'its normaiiowereposiuontheerakearlnwiulfextend Jat an exact predetermined fang-le to the uppercam 'surfaceSI ,'suchthat -u on tlieupwad movemthofthe uitingen-irren# nu camerinopper'camis'urfacewilliengage'fthe roller :35 and move the" crank`4 armdownwardlyaboutitsi aiis, thatis; a ount'eclockwise dettn-` asvwdin'FigfZ, thereby moving-the crank`iarm`22 also inacounterclockwise:direction to "openthedtiofs'- Upontheloonunued-movementof tho'iiftmg nog ment*a`fter*thefdoors *have beenepenedfjtl'ie straight"surfacei33ofithe-"camwill engage-the-`ward1y1fromits Selevated position the lower inclined-"surfacesf of thecam will engage the -ro1ler Eiland move the crank arm 34 again incounterclockwise direction to open the doors I4 ald-wh'enfthesuperstructure has passed into the pit the upper inclined surface 3l ofthe cam will engage the. roller and'permit the ldoors toiclose.Preferably a bracket '36 is mounted 1at onez-side ofthe crank arm andprovided with-Jalstop, such asfa pin 31,to-.-positivelylimit thelupwardmovement of the crank arm.

Thus it willbe apparent that Aw-hen'the superstructure is withinthepit'alllfourdoorswillifbe closed and will form asmoothand'lcontinuous portion of the floor surface. 'iWhen thelift-is in itselevated position the 'sidefdoorsIlfwill'be closed and the transverse*doors `I6 willbe in inclined positions and in -engagement -`with thelifting element, and when those' positions'-'-will prevent ethe foot ofthe-operatorffrom entering the opening II.

While we haveshownVv and described-oncombodiment of ourn invention, wei4wish it "to *be understood that 'werlo not desirelto be 'limited tothe details `thereof yas 4various modifications may 'occur to aperson/skilled in the art.

VHaving fully shown and described our invention, what we claim as newand desire to secure by Letters Patentfis:

l. In an automobile lifting mechanism, averticallyf movable-liftingelement, a superstructure mounted on -said lifting element A formovement therebyv through Aan f opening in a f iloor into and outof apit below -thelevel of `said licor; movable closures forsaid opening,means for moving said c1osuresf-to-`openfpositions including-anactuating mechanism -below said opening `and A'controlled bysaid liftingelement, andmeans for operatively connecting said-actuating V`Imechanisml-withlone of-said closures; said connecting means including afresilientAelement offsulcentstrength to A open said closure Yunder normaloperating vconditions andV adapted to 'yield' and .permit Vsaidactuating mechanismltomovewith relation to saidclosure when-excessiveresistance is'oiferedto the openlng movement of said closure.

l 2. Inv an automobile. lifting mechanism, `a Iverticallylmovableliftingv element,fa superstructure mounted on said liftingvelement for movement thereby lthrouf'gh-an openingin -a'floor into andout Yof a pit beloW'l-the level-of said floor, means for closing saidopeningincludingla hinged-door, door` operatingfmechanism below saidopening controlled -by -s'aidY lifting mechanism and including acrankarm, an actuating' memberv connected with said door,-and means foroperatively connecting l'said cranklarm with said actuating member,`said connecting means including ian element which is-yieldable underexcessive resistance to the-opening movement of saiddoor.

an automobile liftingVv mechanism,4 Aa-vertically movable liftingelement, a superstructure mounted on said lifting element for movementthereby through an opening ina floor into and out of a pit below thelevel of said floor, means for closing said opening including a hingeddoor, door operating mechanism below said opening including a crank arm,means including a rock shaft Xedly attached to said crank arm and a camfollower engaging a cam controlled by said lifting mechanism foractuating said crank arm, a door actuating member operatively connectedwith said door, and means for connecting said crank arm with saidactuating member for movement with relation thereto, and spring means tonormally prevent the movement of said crank arm with relation to saidactuating member and to yield under excessive resistance to the movementof said door.

4. In an automobile lifting mechanism, a vertically movable liftingelement, a superstructure mounted on said lifting element for movementthereby through an opening in a floor into and out of a pit below thelevel of said floor, means for closing said opening including a hingeddoor, door operating mechanism below said opening and including a rockshaft and a crank arm xedly mounted on the rock shaft having mountedthereon a cam follower, a cam controlled by said lifting mechanism andengaging said cam follower for actuating said crank arm, a rod pivotallyconnected with said door, a part connected with said crank arm andslidably mounted on said rod, a stop on said rod between said crank armand said door, and a compression spring confined between said stop andsaid part on said crank arm.

5. In an automobile lifting mechanism, a vertically movable liftingelement, a superstructure mounted on said lifting element for movementthereby through an opening in a floor into and out of a pit below thelevel of said floor, means for closing said opening including hingeddoors, a door operating mechanism below said opening including a rockshaft having a plurality of crank arms mounted thereon, means controlledby said lifting mechanism for engaging one of said crank arms to rockthe other crank arms, rods pivotally connected respectively with aplurality of said doors and to said other crank arms, parts connectedwith said other crank arms and slidably mounted on the correspondingrods, a stop on each of said rods between its crank arm and its door,and a compression spring confined between the stop on each rod and thepart on the corresponding crank arm.

Y 6. In an automobile lifting mechanism, a lifting element, asuperstructure comprising a cross member secured to said lifting elementand parallel rails secured to the respective ends of said cross member,said superstructure being movable by said lifting element through anopeningv in a floor including parallel passages for said rails and atransverse passage for said cross member, a pair of hinged doors forclosing said transverse passage, said doors being arranged to be engagedand opened by said cross member as the latter moves upwardly, a singlehinged door for each of said parallel passages, actuating membersconnected with the doors for the respective parallel passages, operatingmechanism mounted below said opening and controlled by said liftingmechanism, means for connecting said operating mechanism with saidactuating members and including resilient elements adapted to yieldunder excessive resistance to the opening movements of the respectivedoors.

7. In an automobile lifting mechanism, a lifting element, asuperstructure comprising a cross member secured to said lifting elementand parallel rails secured to the respective ends of said cross member,said superstructure being movable by said lifting element through anopening in a floor including parallel passages for said rails and atransverse passage for said cross member, a pair of hinged doors forclosing said transverse passage and arranged to be engaged and opened bysaid cross member as the latter moves upwardly, a single hinged door foreach of said parallel passages, a rock shaft mounted below said opening,means controlled by said lifting element for rocking said shaft,actuating rods connected with the doors for the respective parallelpassages, crank arms secured to said shaft and connected with therespective rods for movement with relation thereto, and springsinterposed between the respective crank arms and the corresponding rodsto yieldably resist the movements of lsaid crank arms with relation tosaid rods.

ION V. K. HOTT. KENNETH E. BERK.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,487,832 Barney Mar. 25, 1924 2,383,136 Laurain Aug. 21, 19452,524,237 Smith Oct. 3, 1950 2,577,377 Snider Dec. 4. 1951-

